# tac(1) - man - phpman

> **TLDR:** Display and concatenate files with lines in reversed order.
>
- Concatenate specific files in reversed order:
  `tac {{path/to/file1 path/to/file2 ...}}`
- Display `stdin` in reversed order:
  `{{cat path/to/file}} | tac`
- Use a specific separator:
  `tac {{-s|--separator}} {{separator}} {{path/to/file1 path/to/file2 ...}}`
- Use a specific `regex` as a separator:
  `tac {{-r|--regex}} {{-s|--separator}} {{separator}} {{path/to/file1 path/to/file2 ...}}`
- Use a separator before each file:
  `tac {{-b|--before}} {{path/to/file1 path/to/file2 ...}}`

*Source: tldr-pages*

---

[TAC(1)](https://www.chedong.com/phpMan.php/man/TAC/1/markdown)                                      User Commands                                     [TAC(1)](https://www.chedong.com/phpMan.php/man/TAC/1/markdown)



## NAME
       tac - concatenate and print files in reverse

## SYNOPSIS
       **tac** [_OPTION_]... [_FILE_]...

## DESCRIPTION
       Write each FILE to standard output, last line first.

       With no FILE, or when FILE is -, read standard input.

       Mandatory arguments to long options are mandatory for short options too.

### -b --before
              attach the separator before instead of after

### -r --regex
              interpret the separator as a regular expression

### -s --separator
              use STRING as the separator instead of newline

       **--help** display this help and exit

### --version
              output version information and exit

## AUTHOR
       Written by Jay Lepreau and David MacKenzie.

## REPORTING BUGS
       GNU coreutils online help: <<https://www.gnu.org/software/coreutils/>>
       Report any translation bugs to <<https://translationproject.org/team/>>

## COPYRIGHT
       Copyright  ©  2020 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later
       <<https://gnu.org/licenses/gpl.html>>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY,  to
       the extent permitted by law.

## SEE ALSO
       [**rev**(1)](https://www.chedong.com/phpMan.php/man/rev/1/markdown)

       Full documentation <<https://www.gnu.org/software/coreutils/tac>>
       or available locally via: info '(coreutils) tac invocation'



GNU coreutils 8.32                          January 2026                                      [TAC(1)](https://www.chedong.com/phpMan.php/man/TAC/1/markdown)